Bridges, Part 1

Our last and final point of emphasis before the end of the school year is learning about bridges.  We are learning about the types of bridges, and specifically, the bridges in and around Portland.

First, we needed more hands-on information about bridges and how they work.  First, experimented with building a truss style beam bridge.  We discussed how triangles make the trusses strong.

Some of us, did a very organized system of trusses.

Others tried a more free-form approach.

Next, we tried to build an arch bridge.  We wanted to see how many cubes the bridge could hold.

We discovered it was easier to hold more cubes if the arch has a defined "deck" on top of the arch.

 Next, we worked on suspension bridges.  The goal was to be able to hang a pair of scissors from the bridge.  Many groups were able to design support towers strong enough to support the 'cable.' 

The students also discovered how important the tension of the cable is.....and that the cable must have a good anchorage.

Through trial and error, we learned a TON about how bridges are constructed, and the best strategies to build strong bridges.  Now, on to the bridges of Portland.